The bipolar coagulating forceps is a common instrument in many branches of surgery, it being heavily used in microsurgery such as neurosurgery and eye surgery where pinpoint coagulation of small bleeding tissue or arteries is required. Bipolar forceps first appeared in the late 1950's and early 1960's, and now are commercially available from dozen's of manufacturers and their dealers. The world's leading manufacturers of bipolar forceps are: Radionics, Inc., Codman and Shurtleff, and Storz Instruments, of the USA; Aesculap Instruments, Karl Storz, and MET Fischer, of W. Germany. Bipolar forceps vary widely in shape and styles, but their functional geometry and means of actuation is always the same. FIG. 1 shows a typical example. They are like regular forceps except that the two forceps arms, 1 and 1', in FIG. 1, are electrically insulated from each other. When 1 and 1' are connected to a high voltage rf potential source 3, and when tips 2 and 2' of arms 1 and 1', respectively, encounter conductive tissue, then electric current heating of the tissue between 2 and 2' will occur. This results in desired coagulation. The arms 1 and 1' define a distal axis A--A' of the forceps. This might also be referred to as the longitudinal axis. The surgeon will direct the axis A--A' to the target, squeeze the arms 1 and 1' together, thus closing the tips 2 and 2' upon the tissue or artery to be coagulated. Once so closed, the surgeon will turn on the electric potential between 1 and 1', and thus between 2 and 2', thereby ohmically coagulating the targeted tissue. This technique and principle is described in detail in commercial brochures.
Note that we will refer to the distal end of an instrument as that which is directed at the patient or target, as the front end of the forceps, and the proximal end as that nearest the surgeon, as the handle end of the forceps. The distal axis A--A' of an instrument is approximately the direction in which its distal end points, as, for example, the direction that the distal arms of a forceps points toward the object it is to contact. Usually when a surgeon aims an instrument down a deep surgical hole to reach a target the distal axis of the instrument is approximately the axis of the surgical hole or the line of sight of the surgeon, especially if he is viewing the target through a surgical microscope. One might also refer to the distal axis of the instrument as the longitudinal axis, which also implies being along the direction that the elongated distal end of the instrument is pointing. An axis perpendicular to the line of sight could then be defined as being transverse to the line of sight.
For all bipolar forceps to date, their tips always close along a transverse direction that is a direction which is perpendicular to the distal axis A--A' of the forceps. Specifically, when the grips 4 and 4' of the forceps arms are squeezed together, then 4 and 4', 1 and 1', and 2 and 2' move together so that the tips 2 and 2' move along a line B--B' which, near the point of closure, is perpendicular to the axis A--A'. Thus B--B' might also be referred to as a transverse axis or direction relative to A--A'. The arms 1 and 1', including 2 and 2' and 4 and 4', are continuous metal conductors, and 1 and 1' are joined at their base by insulating element 5, so 1 and 1' are electrically isolated from each other. The shape of the arms 1 and 1' and their tips 2 and 2' and handles 4 and 4' may vary; i.e. 1 and 1' may have straight or bayonet shape; tips 2 and 2' may be straight bent, or curved up or down by 90.degree.; but the basic forceps axis A--A' and perpendicularity of tip movement axis B--B' relative to A--A' is always present. So in cases where the surgeon is looking into a deep surgical hole, as shown in FIG. 2A, then the direction of the hole would be forceps axis A--A', and one can only close tips 2 and 2' on tissue to be coagulated in a direction B--B' perpendicular to A--A', i.e. perpendicular to the surgeon's line of sight. This is a severe restriction in certain surgical situations, as will be shown below.